JavaScript rounding to negative decimal places like Excel

Question

I am trying to round a number in JavaScript to match the following Excel style rounding.

Excel:

=ROUND(123456,-1)

which outputs

How can I get JavaScript to round to negative decimal places?

score 5 · Accepted Answer · answered Mar 23 '12 at 01:06

5

function round(x, places)
{
    var shift = Math.pow(10, places);
    return Math.round(x * shift) / shift;
}

answered Mar 23 '12 at 01:06

Kendall Frey

1

You shouldn't start a function on the next line, start it on the same line as the declaration. – Elliot Bonneville Mar 23 '12 at 01:08
@ElliotBonneville: What do you mean? – Kendall Frey Mar 23 '12 at 01:09
The upper `{` needs to go on the same line as `function round(...)`. I can't exactly demonstrate, since comments don't allow linebreaks. – Elliot Bonneville Mar 23 '12 at 01:10
2

@ElliotBonneville: No it doesn't. – Kendall Frey Mar 23 '12 at 01:10
1

@ElliotBonneville: No it doesn't. It is simply a matter of personal preference. I prefer it this way. – Kendall Frey Mar 23 '12 at 01:15
2

A function requires a block. The interpreter won't ever assume that a blockless function is a valid statement, unlike a argument less return. – J. Holmes Mar 23 '12 at 02:08

score 0 · Answer 2 · answered Jan 04 '13 at 18:44

0

Formula.js implements all Math functions offered by Microsoft Excel 2013, including ROUND.

answered Jan 04 '13 at 18:44

Ismael Ghalimi

2 Answers2